OK what the hell

[1st6.0GTO]

How exactly does your car acting strange have anything AT ALL to do with our level of support?
Did someone pee in your Cheerios before you made that post?

The first reply came from one of the most experienced and knowledgable tuners in the industry, which I call having great support...
Then, Lew tries to rationalize it by explaining that weather will effect the trims, and you slam him too?

Man, chill out...these guys have helped you since day one, thats no way to say thanks.

Mike, I didnt say the car was acting strange, I said I thought it was strange that the LTFT went from - (for well over a month) to + out of the blue. I never saw that with my 06, and up till my OP, never saw that with this 04. Johan did respond and I was all set to just follow his advice, till I go to speaking to others on the LS forum, then Lew posted on here the " I was screwed, ha ha" and then the post got deleated seconds later. At the time I wasnt in a joking mood, and I was concerned that there was a problem with my car. At that point those were the only post on the forum and the more I talke to a guy on the LS forum the more I came to understand the how and why it went from - to +. Now Im fine and yes the LTFT are still +, but the car still feels good and strong. I guess as the old saying goes each car is differant and mine likes to be in the + more than - as far as LTFT.
Plus a group of here in my area are trying to get a dyno/tuning day gtg at a local shop, so then I will tweek it on a dyno with AFR and be a little more at peace.
So no one pee'd in my O's, I was just surprised of the little responce I got till I agitated

[hairytool]

I too have experienced this in my truck. I stopped trying to tune with the LTFTs and bought an Inovate wideband O2. Every time I adjusted my trims; a few weeks later they were back! I started tuning with the wideband and could actually see this happening. I adjusted the trims to run very rich and drove for several weeks. They slowly but surely returned to 14.5-14.6 AFR. Then I trimmed it out lean and, again, drove for several weeks as it slowly returned to 14.5-14.6:1 AFR! Maybe I have peepee in my cerial too! Its kinda weird how it seems to revert back to a mysterious preset AFR setting. I'm still watching to see if my WOT AFR changes stay where I set them.

[1st6.0GTO]

I too have experienced this in my truck. I stopped trying to tune with the LTFTs and bought an Inovate wideband O2. Every time I adjusted my trims; a few weeks later they were back! I started tuning with the wideband and could actually see this happening. I adjusted the trims to run very rich and drove for several weeks. They slowly but surely returned to 14.5-14.6 AFR. Then I trimmed it out lean and, again, drove for several weeks as it slowly returned to 14.5-14.6:1 AFR! Maybe I have peepee in my cerial too! Its kinda weird how it seems to revert back to a mysterious preset AFR setting. I'm still watching to see if my WOT AFR changes stay where I set them.

From what I have read and discussed with others the ECM will bring it back to the 14.7 as it was ment to run. I have also heard that tuning by this method Slope Adj if kinda a waist because if this. if your at 0 during WOT then great and now that you have a WB you can tweek the PE to get the AFR at WOT to reach the 12.5-13.0. I know that the LTFT does have some effect on the WOT fueling, thats why I say if your seeing 0. Im planing on bumping my slope +1 or -1 if needed, to keep the WOT fueling at 0, and to reduce any KR I get. SO I guess thats what I am experiancing, the ECM trying to bring it back to 14.7

[06MonteSS]

at normal driving / part throttle - yes, the ECM will always adjust the fueling to maintain the stoich 14.75 value... this is what the ltft's are for afterall...

but by adjusting the injector slope, you also affect the WOT fueling, because you're making the injectors spray less or more fuel...

if you get your average ltft's in the 0 to -2 range during normal driving/cruising by adjusting the injector slope, your WOT / PE fueling will also be correct and give you a WOT AFR of around 12.6 to 12.8... at least it does on the LS4's anyway...

the whole point of trying to get the ltft's at or around 0 is so that the ECM is not having to correct the fueling as much, which gives you the best performance and also makes your WOT / PE fueling and AFR more predictable and easier to tune...

[1st6.0GTO]

True, but again its obvious that each car/truck is differant, like mine seems to like being a little on the + side of the slope. Until i gat ona dyno with afr to know for sure, I have to go by how the car drives and feels.

[06MonteSS]

correct...

[FastBlueSS]

to hairy tool, you can adjust those trims all day long but at cruise you should always be at 14.75. The only time you should even look at your wideband is when you are at WOT.

[1st6.0GTO]

Thats the same thing I said, Wish I never got rid of my 06 goat, already had all this stuff dialed in, plus I had a wideband.

[hairytool]

Then what is the point of adjusting the injector slope? I can adjust my slope to -6, and after several weeks it will eventually return to +1.xx! This appears to be the preferred LTFT in my computer. Now my settings still say -6(not my actual settings just an example; I leave my injector slope @ 0.00 now) but the average LTFT's will always return to +1.xx. I understand how to use an AFR guage(use mainly to monitor WOT AFR, BLAH,BLAH, etc.) I was just using it as a tool to confirm my suspicions that the injector slope adjustments in my predator were not holding. It's no big deal, just weird. Again, like I said it always returns to 14.5-14.6AFR(cruising) My truck seems to like a little more fuel. Even at WOT it runs harder at 12.1-12.5AFR.

[1st6.0GTO]

Very true hairytool. Mine were in the + on Monday (just like last Friday), but yesterday they went back -. The weather on Friday and Monday was close to the same. Tuesday was a little cooler. I didnt log it today but will tomorrow and also this weekend. Im gonna try the bumping the slope +1 or -1% at a time. But like you mine seems to like the + side of the slope, it eliminated my KR and gave me some timing at WOT, even tho I was + on the LTFT my WOT trims were still 0.

[1st6.0GTO]

After not getting a chance to do a good long data view till today. The weather is about the same as when I made this thread last friday, rainy and kinda humid. Well my trims started out in the - again (0.00> -.78) and after driving for about 1/2 hr -45min and making a stop, then heading back home they then went to the +. Not as bad as when I made this thread but still + (1.56>2.96). So I got to thinking, I could understand If it got real cold out and the ECM was wanting more fuel to be on the +, but its in the 50's and IAT's were in the mid to high 60's. Again if its cold then it would explain lean (ltft being +). Then I thought of all the threads I have read here latley about what I have started here (on this forum and DS) and this same issue every one seems to be running into the same thing, going from - > +. If my Pred U7193 was able to make use of the DS Redux file app then it would be telling my to bring my Inj Slope to another -2>3 to bring the LTFT to 0 or -2. That would be a total on my current set up of (current -4) -6> -7. To me that doesnt make sence, if it a little warmer out and the humidity is up I could understand it wanting to be a little leaner, not rich.
SO I have come to a conclusion why even bother adjusting the slope. I understand DS's idea is to get the fueling on the LTFT as close to 0 to then not add anymore to the PE during WOT. But if the LTFT are gonna always be all over the place and constantly change as they are now duing then why, whats the point. Why not leave them at 0 (default) and only work on the PE? Again since the LTFT is always gonna change to reach 14.7. Leave them alone and worry about WOT fueling only.
Just a question/statment/idea.

[1st6.0GTO]

But my thoughts are this, + on the LTFT means your lean and the computer is adding that much fuel to meet the 14.7, and of course - on the LTFT means your rich and taking away fuel to again meet 14.7. My point is this, when Im at cruise and under a load, or not and my LTFT is in the - if I go WOT during that - I see KR and start pulling 2-3* of timing. Now when Im in the + during normal cruise and WOT during that + I see no KR and thus nothing pulled. Now keep in mind during - or + at WOT I still see 0 on the trims. This is again with a current -4 on my slope. I dont understand how that can be. Also to add, in theory, on a warm day and or more humid day you should be running a little rich, and the opposite on a cooler day. When I set these LTFT it was in the low 30's and IAT's were around 35-40* and low humidity, today like last friday, temps were in the mid 50's and IAT's were in the mid to upper 60's. So with the cooler temps my trims are saying Im in the -, but on the warmer days my trims are in the +. Dosent make sence. Cooler to me means it should be adding to the slope, and warmer it should be taking away. Mine arent doing that. Like today and last friday my trims were in the + meaning Im lean and its adding fuel, but its warmer out and more humid, and during the week I was in the - meaning it is rich and taking away fuel but the air temps were in the 30's-40's. Im just not understanding why mine seems to act in a backwards fashion, and runs better on the + side of the slope.
This is my current set up, maybe some one see's something Im missing.

Winter tune

1/18/08
8:30am-1030am

04 A4 GTO
Mods-
K&N Drop in w/mod'd airbox
Ported & Polished TB, w/bump stop mod,knife edged butter fly,throttle shaft halfed
SLP LM1 catback w/resornators removed
U7193 Predator tuned

Weather- Huntsville AL
40ish, Sunny, Low humidity
Intake Air temps were in the low 50's

Predator Tune
Cruise @ 75mph
LTFT Bank 1&2
1.56/2.34
WOT>130 mph
LTFT Bank 1&2
.56/.56

After First Adjustment
Adjusted LTFT to -2
Timing advanced to (4k-7k) 2%
LTFT Bank 1&2
.78/1.56
No WOT due to traffic

After Second Adjustment
Adjusted LTFT to -4
Timing advanced to (4k-7k) 0%
LTFT Bank 1&2
0.00/-0.78
WOT>145mph
LTFT Bank 1&2
0.00/0.00
O2 volts
.87x/.87x
Timing 19-20 Deg.

Keep in mind when I set this tune up I wasnt seeing any KR, but as time went on I have been seeing 2-3* of KR at 4750 rpm and^ after a downshift at WOT, when the LTFT started in the -. Nothing as far as KR when my LTFT starts in the + during normal cruise.

[S10HotRod]

Way too much reading...

[hairytool]

Sounds like we're on the same boat to nowhere. Thats why I decided to return my slope back to 0 and let the computer do its thing! It seems our vehicles will set the trims to where it wants anyway and its no fun trying to readjust slopes every time they change. Plus I've reflashed my PCM (with handhelds) at least 3-4 dozen times in the past three years and I've been fortunate so far not to screw the PCM. Good time to stop pressing my luck! If I tried to maintain a LTFT of -2--0 ; I'd have to reflash my PCM every 4-6 weeks. Thats sure to f%$k somthin up!

[1st6.0GTO]

Yea thats what Im thinking, my LTFT werent that far off from the base Pred tune. WOT did have a little added to it. SO I was thinking of doing one of 2 things. 1. Returning trims back to default (0) and adding just a little to the PE. or 2. Returning my trims to -1 or -2 which ever minimal adjustment will net me a 0 at WOT.
Then just monitor everything as the weather gets warmer. Spring and summer.